Table 1_Study on the antibacterial effect of the new anti-biofilm inhibitor ICAC on Escherichia coli.docx

The rise of bacteria antibiotics resistance has bacome increasingly severe, and the development of natural compounds with antibacterial activity represents a promising approach to combat this issue. The efficacy and mechanisms of the plant-derived phenolic compound isochlorogenic acid C (ICAC) as an antibacterial and antibiofilm agent against E. coli were investigated. The study utilized a comprehensive approach encompassing crystal violet staining, scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), the ruthenium red method, semi-solid agar motility assays, and quantitative real-time PCR (qRT-PCR) to elucidate the inhibitory effects and their underlying mechanisms. Results revealed that ICAC exhibited significant antibacterial and antibiofilm activity against E. coli. The results demonstrated that ICAC could inhibit the biofilm formation of E. coli, reduce the biomass of preformed biofilms, and decrease the production of extracellular polysaccharides (EPS) and extracellular proteins, as well as bacterial motility. Moreover, qRT-PCR results showed that ICAC downregulated genes associated with c-di-GMP synthesis while upregulating those involves in c-di-GMP degradation, thereby inhibiting biofilm formation and bacterial motility. In summary, ICAC shows potential as an effective anti-c-di-GMP agent and a novel antibacterial candidate for the treatment of E. coli infections.